There is nothing, other than a unique design, that makes a Mac worth more than a PC. In fact, if you take the price you pay for a Mac and put it into a PC you'd end up with a much faster machine, hardware wise.

The manufacturer for Apple mainboards is Asus, just like it is for Dell, HP, Compaq, etc. (for the most part anyway, I know there are exceptions)

I think you're mostly paying for the funky design, much like you pay more for a laptop than you do an equivalent desktop.

The build quality and the hardware used is second to none. That *IS* a good reason

Also, simplified, easy to use OS for all basic computer usages. Internet, Email, Photos & Videos, Music, Chat all ready to go out of the box. I guess it's not as "complicated" as Windows *can* be. Shizz usually just works too.